With an increased focus on environmental impact and on health, there is an interest and/or a need to find replacements for existing reagents to reduce environmental and health risks associated with toner production and use. Some current polyester-based toners are composed of fossil fuel-based materials, including bisphenol A (BPA). BPA has been linked to a variety of health concerns. Several Europe countries, Canada and several U.S. states are targeting a ban of BPA.
Renewable or biodegradable reagents and materials, such as, those which are plant-based/animal-based or which are biodegradable, are being investigated as replacements for current toner reagents.
Polyester resins using renewable materials may be produced with inferior color, especially when long process time is involved. When Gardner Index color is poor, the resin may be discarded.
It is desirable, then, to employ a process which produces polyester resins from, for example, sustainable materials, having superior color properties.